A Force and motion problem

Suppose a horse pulls on the rope with a force of 7134.064422651 N at an angle of = 18.955585914° to the direction of motion of a barge, which is headed straight along the positive direction of an x axis. The mass of the barge is 9358.240127247 kg, and the magnitude of its acceleration is 0.155965913 m/s2. What are (a) the magnitude and (b) the direction of the force on the barge from the water?

You can find the component of the horse's force along the barge using trigonometry, correct? Since you know the net force on the barge = force of horse + force of water, and you know the numerical value of the force on the barge (=barge's mass * acceleration), you should be able to find the force of the water on the barge. It should be slowing or speeding up the barge...check and see. :)